Refrigerating machine



c. H.s'rE-Elusj-R'UP4 REFRIGERATING MACHINE Fi1 ed Feb. 17, 1957 Oct.f1s, 1938.

vhu/evfcov: y Cen-'l H. Steenstrup,

)Vm/'y' His f Attorney Patented Oct. 18, 1938 REFmcEnATmG MAcnnvE CarlH. Steenstrup, Schenectady, N. Y., assignor toGeneral Electric Company,a corporation oi' New York Application February 17,

5 Claims.

My invention relates'to compression type rel frigerating machines, andincre particularly to an improved construction and arrangement of n anintake muilier therefor.

Compression type refrigerating machines are frequently provided with acompressor and a driving motor enclosed in a casing which'is preferablyhermetically sealed, thus obviating the necessity of using connectionswith packing glands or the like between the motor land compressor, andminimizing leakage of refrigerant from the. machine, as any gaseousrefrigerant which escapes from the compressor is confined in theenclosing casing. It is desirable that theenclosing casing be providedwith a lubricant reservoir for containing a body of lubricant which isrecirculated to the bearings and moving parts of the motor andcompressor during operation of the machine without the necessity ofvariation and replenishment, thus simplifying the maintenance of themachine. In order to minimize the transmission of operating noises ofthe compressor through the enclosing casing to a refrigerator cabinet itis desirable 'that an, intake muf- 25 fier be associated with the intakeport of the compressor.

During the operation of a refrigerating machine of this type it is veryimportant that no appreciable quantity of the body of lubricant 30contained in the lubricant reservoir formed in the enclosing casing bedr'awn into the cylinder of the compressor through the intake muiller,asV the presence of lubricant in the compressor cylinder would give riseto excessive pressures in B5 the cylinder resulting in damage to thevalves of the compressorylubricant being a non-compressible fluid. Inactual practice, it is diilicult to prevent lubricant from being drawninto the cylinder of the compressor as the body of lubricant' icontained in the lubricant reservoir formed in the enclosing casingoften becomes `frothy'and rises considerably above its `normal operatinglevel in the enclosing casing into the intake zone of the intakemuilier. Furthermore, during the i assembly and shipment of such arefrigerating machine the enclosing casing oftenlbecomes tilted from itsnormally upright. position allowing a portion of the body of lubricantcontained .in the lubricant-reservoir to spill into the intake muilier,

i0 from which it is drawn into the cylinder of the compressor when themachine is started.

It is -an object ofmy invention to provide an improvedarrangement of theintake muiiler in an enclosed compression type refrlg rating mai5 chinein order to prevent frothy lu riant from 1937, Serial No. 126,206

gaining entrance intovthe intake muiller 'and the cylinder ofthecompressor. Another object of my invention isto provide an improvedintake muiiier construction for com' pression type `efrigeratingmachines which em- 5 bodies an arrangement providing for the escape fromthe intake muiiler of any lubricant accumulated therein.

Further objects and advantages of my invention will \become apparent asthe following de- 10 scription proceeds, and the features of noveltywhich characterize my invention will be pointed out with particularityin theclaims annexed to and forming a part of this speciflcation.` For abetter understanding of my invention m reference may be .had to theaccompanying drawing, in which Fig. 1 is a side elevation, partlyinsection, of a refrigerating machine embodying my invention; Fig. 2 isa vertical sectional view or tne'mtake mumer shown in Fig. 1; F1g:3 is a2 sectional view of the intakemuiiler alongthe line 3,-3 of Fig. 2; Fig.4 is a vertical sectional view of a modified form of the intake muffler4shown in Fig. 2; Fig. 5 is a plan view f the intake muilier shown inFig. 4; and Fig.'6 is a fragmentary side 25.

elevational view taken in the direction of the' arrow 6 in Fig. 1 of therefrigerating machine.

Referring to the drawing,A in Fig'. 1 I have. shown a refrigeratingmachine ofthe household type provided with a. hermetica'lly rsealedcasing I0 made of an upper casing section II and a lower casing sectionvI2, the adjacent edges of .these casing sections being welded togetherat I3 over-a reinforcing ring I4. `The casing seco. tions II and I2 arepreferably made of steel and 35 -are mounted on a removable cabinet topI 5. 'A"

refrigerant compressor I6 and an electric driving motor I1 therefor areenclosed within `the hermetically sealed casing I. v 'I'he compi-'essorvI6 is secured to the top of the driving motorv I'I by'40 a series ofbolts I8, thus formingacompact unitary structure. This unitary structureis mountn y edin the casing I 0 onthree vertical springs I9,"V 20 and2|. 'The upper'ends of the springs I9, .20 and 2| are` secured tofeetv22, 23 and 2l, respec- 45 tively, these feet being welded to theperiphery of the frame ofy the motor I'I- at equally spaced intervals'.A lubricant reservoir I2a is formed in 1 the lower casing section v12and contain'zfia body of lubricant therein which is recirculated fromthe lubricant reservoir t the bearings and moving parts of the motor andthe compressor-during operation of the machine. .v-Also gaseousrefrigerant is conned in the upper portion ofthe enclosing casing Il. v

lAs best shown in Fig. 6, the driving motor I1 has a substantiallyvertically disposed shaft 25 which extends above the upper end shield ofthe driving moto and reciprocates a compressor pist0n 23 in asubstantially horizontal cylinder of i the compressor i3 through asuitable driving connection 21. Preferably,.the driving connection is ofthe Scotch yoke mechanism type including a crankpin 28 and a cross-head23 slid- 'ably carried by the end of the piston 23. A counvports areprovided in the compressor cylinder in communication with a muflle box3| secured to the compressor I3 adjacent the outer end of the horizontalcylinder by a series of bolts 32. A cylindrical intake muffler 33 issecured to the lower end of a depending intake conduit 34. the

retracted on lits suction stroke the pressure withi in the cylinder isreduced and gaseous refrigerant is drawn into the cylinder from .theupper portion of the enclosing casing I 0 through the intake muiller 33,the muille box 3| and the intake valve of the cylinder. -When the piston23 in the compressor cylinder is moved in the opposite direcupper end ofwhich is secured to the muille box 3| in communication with the intake.port of the cylinder of the compressor I3. A cylindrical exhaust muiller35 is secured to the lower end of a depending exhaust conduit 33. theupper end of which is secured to the muille box 3| in communication withthe exhaust port of the cylinder of the compressor I3. A plurality ofrelatively long restricted tubes 31 havine` return-bend portions securedin openings provided inthe intake muffler 33 provides communicationbetween the plane.

upper portion of the enclosing casing I3 and the interior of the intakemuiller 33.

When the refrieerating machine is first startedthe bndv of lubricantcontained in. the lubricant reservoir I 2a formed in the enclosingcasing I0 tion on its compression stroke the gaseous refrigerant withinthe cylinder is compressed and discharged through the exhaust valve ofthe cylinder and the muille box 3| into the exhaust muiller 35. 'I'hecompressed gaseous refrigerant passes from the exhaust mutller 35through a conduit 33 to a condenser 40 which is cooled by natural draftand which surrounds the enclosing casing I0, the condenser having apassage 4|. therein, preferably divided into upper and lower portionswhich are connected in series by a conduit 42. The compressed gaseousrefrigerant is liquefied in the con-4 denser 4|)A and flows therefromthrough a conduit 43 to a suitable ow controlling oat valve 44.

Liquid refrigerant is supplied from the flow controlling fioat valve 44through a liquid line 45 to a sheet metal flooded type evaporator 43.v'I'he evaporator 43V is supported in the food storage compartment of therefrigerator cabinet by the heat insulated removable cabinet ,top l5.The

liquid refrigerant contained in the evaporator 43 is vaporized by theabsorption o f heat from articles contained in the-food storagecompartment in whichthe evaporator is located and the vaporizedrefrigerant is collected in a cylindrical header 41' which is normallymaintained about half full of liquid refrigerant. The vaporizedrefrigerant which is accumulated above the level of the liquid becomesfrothy and rises above its normal level inl the enclosing casing due tothe reduction of the pressure within the enclosing casing. causing the'gaseous refrigerant absorbed in the body of lubricant to separatetherefrom. Even though .the bodv of .lubricant contained in thelubricant reservoir |2a becomes frothy and rises in the enclosing casingII! when the machine is started or any time during the operation of themachine, it can-` stantially in the plane' indicated by the broken line38 due to centrifugal force, which further prevents the frothy lubricantin the lower portion of the enclosing casing I3 from rising above thisThe movement of the counterwei'ght 30 in the plane substantially normalYtothe vertical shaft 25 thus suppresses frothing of the lubricant inthe upper portion of the enclosing casing and establishes a zonesubstantially free of frothy lubricant in the upper portion of theenclosing casing above the plane indicated by the broken line 33. Theinlet ends of the tubes 31 communicate with this zone in the upperportion of the enclosing casing II! above the plane indicated by thebroken line 38, thereby positively insuring that no frothy lubricantwill be drawn into the intake mumer 33 along with thegaseous'refrigerant during the operation of the machine.

As'the piston 23 in the compressor.. cylinderis refrigerant in theheader 41 is returned to the interior of the enclosing casing l0throughv a sucl -tion conduit 48 which communicates with the 'header 41above the normal liquid level therein.

It will be noted that the discharge end 48a of the suction conduit 48 islocated above the normal level of the body of lubricant contained in thelubricant reservoir |2a formed in the lower casing section I2 of theenclosingicasing I0. The vaporized gaseous refrigerant thus dischargedin the enclosing; casing I3 is again drawn into the y lubricant in theupper portion of the enclosing orator 43 is located is cooled to thedesired temperature. It will be noted that the upper portion of theenclosing'casing I3, above the level of the body of lubricant in thelubricant reservoir |2a therein, is normally filled with low pressuregaseous refrigerant. Any gaseous refrigerant which may have been trappedin the body of lubricant while the machine is at rest will be releasedfrom this body of lubricant after the machine has run a short time andwill again be mingled with the low pressuregaseous refrigerantthereabove.

Preferably, the intake munler 33 is formed of sheet metal, one formvofwhich is shown in Figs. 2

ployed kin'series to obtain the muiliing affect desired. Each of thecasing sections is of cupshaped configuration comprising an end wall, acylindrical side wall and an outwardly flared open end. Theoutwardlyaredeopen ed 32 of -In the illustratedl the upper casingsection 88 receives the end wall i 63 and rmly grips the cylindricalside wall of the casing and is provided witha restricted passage 64therein affording communication between upper and lower chambers 65 and66, respectively, in the muiiier casing. A plate 61 is rigidly sethenflows from-the lower chamber 66 through the restricted passage 64 formedin the end wall 63 of the lower-casing section 6| into the upper chamber66 of the muiller casing. 'Ihe gaseous refrigerant is then drawn fromthe upper chamber 65 through the depending intake conduit 34 into themuiile box 3| and the intake of r the compressor I6. Any lubricantgaining encured in the outwardly flared open end 68 of the d lowercasing section 6I by brazing or the-like.

Thefend of the return-bend portion of each of the tubes 31 is secured bybrazing in openings 63 provided in the plate 61. e lower end of thedepending intake conduit 341 secured by brazing in a restricted passage10 'formed in the end 'wall 1| of the upper casing section 60. Theintake conduit 34 has an external diameter such that it may be. snuglyreceived in either of the restricted passages 10 or 64 in the upper orlower casing' section 60 or 6I, respectively, so that when che respectto the axis of the extended 'intake'mufiler is assembled any of a largenumber of similarly formed casini lsections may be placed in anyorder'in the series. Preferably, each of the tubes 31 is provided withan inlet end or opening 12 disposed at a relatively sharp angle withportion of the tube invorder to minimize the whistling noises producedby the entrance of the gaseous refrigerant into the tube. Also, theendof the returnbend portion of each Vof the tubes 31 received in theopening 63 formed in the plate 61 is provided with an outlet end oryopening 13. disposed ata trance into-the muiiler casing 33 will escapethrough Ythe restrl ted aperture 14 provided in the plate 61 andVdrained back into the lubricant reservoir |2a.

In an intake mumer vsuch as I have illustrated in Figs. 2 and 3,designed for use in conjunction with a sulphur dioxide refrigerantcompressor, two tubes 31 should be employed to conduct gaseousrefrigerant into the muiller casing 33. Each of the tubes should have areturn-,bend portion and an overall length approximately 50 times theinternal diameter thereof so that an extended reverse-flow muiiling pathof restricted cross-section is formed between the inlet and utlet'endsof the tube. The columns of gaseous refrigerant in these tubes have asufliciently high inertia that the energy of the wave motion set up inthe gaseous refrigerant within the depending intake conduit 34 and thechambers 65 and 66 in the muiiler casing is substantially all dissipatedin moving such columns of gaseous refrigerant. The volume of themuliierchambers 65Vand 66 should be relativelylarge as compared to that.

ofthe tubes 31, both the internal diameter and the hightof each of thechambers being of the order of 9 times the internal diameter of therelatively sharp angle with respect to the axis of the return-bendportion of the tube in order toV further minimize the whistling noisesproduced by the gaseous refrigerant emerging from the tube-into thelower chamber 66 in the muiiier casing.

A restricted aperture 14 is provided in the plate 61 which aordscommunication between the lower chamber- 66 lin the muilier casing andthe interiorof the enclosing casing lilto provide for the escape fromthe lower chamber 66 of any,

lubricant accumulating therein, and to allow this e lubricant to bedrained back into thelubricant reservoirA I2a formed in the lower casingsection I2. The area of the restricted aperture 14 is small ascomparedto theareaof the tubes31'in order to insure that the pressure dropthrough `the restricted aperture 14 is relatively great as.

intake muffler as above described is described and claimed in mycopending application, Serial No. 161,075, led August 26, 1937, which isa division of the present case.

During the operation of the refrigerating ma-A chine gaseous refrigerantis drawn into the lower "jchamber 66 of the `intake mufller 33 from thezone'substantially free of frothy lubricant in the upper portion of theenclosing casing I8 through the relatively long restricted tubes 31having return-bend portions. The gaseous refrigerant tubes 31. Also,the' volume of the muffler casing should be somewhat larger than thevolumetric displacement of the piston in the cylinder of the compressorin order to provide a reserve supply of .gaseous refrigerant in themunier casing thereby lminimizing the surges of gaseous re frigerantwinto the compressor on the 4suction turbances.

In Figs. 4 and 5 I have shown a modified form of the intake muffler 33comprising complementary upper and lower casing sections 80 and 8|,respectively, of substantially cup-shaped conguration. The upper casingsection 80 is pro- 'stroke and the accompanying vibratory disvided withan outwardlyflared open end-82 and the lower casing section 8|v isprovided with an inwardly flared open end 83, the inwardly flared openend -83 being received and rmly gripped within the outwardly flared openend 82. vThese casing sections may be brazed or otherwise rigidlysecured together. However, I prefer that the iit between the outwardlyflared` op'en end82 and the inwardly flared open end 83 be suiilcientlytight to hold the muiller casing in assembled re lation by friction. Atransverse partition. 84 is arranged in the upper casing section80 inabutting relationship with the inwardly flared open end 83 of the lowercasing section 8i. The partition 84 is provided with a restrictedpassage 85 therein forming communicating upper and lower chambers 86 and81 in the muiller casing. The end wall 88 of the upper casing section 88is prosa l vided with twg spaced apart openings 83 in I verticalalignment with two spaced apart openings 90 providedy in the transverse.partition 84 through which two relatively long restricted tubes 3| areinserted into the muffler casing.' Each of the tubes 9| extends throughthe endv wall 88 of the upper casing section 88, the upper chamber 86,and the transverse partition 84, into the lower chamber 81. 'ThetubesI/are of sufiicient length so as to communicate with the. zonesubstantially free of frothy lubricant in the upper portion of theenclosing casing Ill, when the intake muilier illustrated in Figs.v 4and 5 is employed in the refrigerating machine. Preferably, each ofthetubes 9\| is provided with an inlet end or opening 92 disposed atarelatively 'y sharp angle with respect to the axis of the tube and anoutlet end 93 disposed adjacent the end wall 94 of the lower casingsection 8|. The lower end of the depending intake conduit 34 is securedin an opening 95 provided in the end wall 88 of the upper casing section80. I

The end wall 94 of the lower casing section 8| is provided with acentrally disposed and inwardly extending indentation 96 which definesan annular reservoir 91 in the end wall 94. A restricted aperture 98 isprovided in the'inwardly extending indentation 96 which aiordscommunication between the lower chamber 81 and the interior of theenclosing casing I8 to provide for the .escape from the lower chamber 81`of any lubricant accumulated therein, and to permit this lubricant tobe drained back into the lubricant reservoir |2a formed in the lowercasing section I2. It will be observed that the lower ends 93 of thetubes 9| are arranged out of alignment with the restricted aperture 98provided in the inwardly extending indentation 96 V'to prevent thegaseous refrigerant emerging fromthe outlet ends 93 of the tubes 9| frominterfering with the escape of lubricant accumulating in the annularreservoir 91 throughthe restricted aperture 98. 'Ihe area l of 'therestricted aperture 98 is small as compared to the area'of the tubes 9|in order to insure that the pressure drop through the restrictedVaperture 98 is relatively great as compared to the pressure dropthrough the tubes 9|. 'I'his ar'- rangement insures that substantiallyno gaseous refrigerant will be drawn into the lower chamber 81 of themuiller casing through "the restricted aperture 98, yet lubricantaccumulating therein will be permitted to escape.'

During the operation of the refrigerating machine gaseous refrigerant isdrawn into the lower chamber 81 of the intake muiller from the zonesubstantially free of frothy lubricant in the upper portion of theenclosing casing I8 through .the relatively long restricted tubes 9|.The gaseous refrigerant flows from the lower chamber 81 through therestricted passage 85 formed in the `transverse partition 84 into theupper chamber 86 of the muffler casing.` The gaseous refrigerant is thendrawn from the upper'A chamber 88 through the depending intake conduit34 into the mufile box 3| and the compressor I6. Any lubricant gainingentrance into the muiilr casing 8| two tubes 9| should be employed toconduct gaseous refrigerant into the muiiler casing. Each of the tubesshould have an overall length approximately 40 times the internaldiameter thereof so that an extended muiiling path of restrictedcross-section is formed between the inlet and outlet ends of the tube.Also, the outlet ends of the tubes should extend into the muilier casingin close proximity to the end wall 94 of the lower casing section 8| sothat the end wall ver mumer sucnas :t have inustrad serves as a baillefor the gaseous refrigerant emerging from the tubes to reverse thedirection of flow thereof. The columns of gaseous refrigerant in thesetubes have a sufficiently high inertia that the energy of the wavemotion set up in the gaseous refrigerant within the depending intakeconduit 34 and the chambers 86 and 81 in the muiiier casing issubstantially all dissipated in moving such columns of gaseousrefrigerant. The volume of the muiiler chambers 86 and 81 should berelatively large as compared to that of the tubes 9|, the internaldiameter of each of the chambers being of the order of 9 times` theinternal diameter of the tubes 9| and the overall height of the twochambers being approximately twice the diameter of the chambers. Also,the volume 'of the mui'iier casing should be somewhat larger than thevolumetric displacement of the piston in the cylinder of the 4compressorin, order to provide areserve supply of gaseous refrigerant in themuil'ier casing thereby minimizing the surges of gaseous refrigerantinto the compressor on the suction stroke and the accompanying vibratorydisturbances.

While I have shown a particularl embodiment of my invention inconnection with a household type of refrigerating machine, I do notdesire my invention to be limited to the. particular construction shownand described, and I intend in the appended claims to cover allmodications within the spirit and scope of my invention.-

What .I claim as newl and desire to secure by Letters Patent of theUnited States is:

l. A refrigerating machine comprising a compressor, a motor for drivingsaid compressor, an enclosing casing for said compressor having alubricant reservoir in the lower portion thereof containing a body oflubricant and gaseous refrigerant in the upper portion thereof, meansfor establishing a zone inthe upper. portion of said enclosing casingsubstantially free of any said enclosing casing, an intake muiiier for-said -compressor, means including an inlet opening arranged in saidzone for conducting gaseous refrigerant from said zone to said munier.`and means for conducting gaseous refrigerant from said muiiier to saidcompressor.

3. Arefrigerating machine comprising a vertical shaft motor,ajcompress'or having a cylinder .supported on top of said motor. anenclosing casing for said motorand said compressor having frothylubricant present' in said enclosing cas- 4 ing, an intake muiiler forsaid compressor, meansl a lubricant reservoir in the lower portionthereof e containing .a body of lubricant and gaseous re frigerant inthe upper portion thereof, means including an eccentric counter-weightcarried by the upperportion of said shaft for counteracting dynamicunbalance of said compressor and for establishing a zone in the upperportion of said enclosing casing substantially free ofany frothy 7 saidenclosing casing, an intake vmuiiierfor saidv i compressor arranged insaid enclosing casing, 20

V V l 1 251334,876

ducting gaseous refrigerant'fro'mv said zone to?l said muiiler, andmeans including "a conduitfor' conducting gaseous refrigerant from saidmulerA to said compressor cylinder.

4. A refrigerating machine.comprisingaxcom-l pressor, a motor for,driving said compressor, an-

conta'imng a'body 0f lubricant and. gseous'r;

in' the upper portion of said enclosing casingsubstantially free of anyfrothy lubricant present in means including an inlet opening arrangedlin said zone to said muiiler, a restricted-'aperture in" said muilierand arranged to provide for .theescape from said muiiler of anylubricant acci'x-l f mulating therein, and means for* conducting gas'-presser.

I l5'. `A refrigeratingmachine comprising a compressor; a-motor fordriving said compressor, an enclosing casing-forlsaid vcompressor andsaid 'motor havirigva.v lubricant reservoir formed inv the lower portion.-thereof containing a body of lubricant and gaseous refrigerant in theupper portion thereof, '.meansoperated by said motor z :forestablishinga zone in the upper portion of said enclosing casingsubstantially free of any c 1 .frothylubricant present in said enclosingcasenclosing casing for said compressor -havin'gj'av lubricant reservoirinv the lowerp'ortion"tlaecof partition in.' said mumer casing andprovided with cfl communicatingchambers in said muiiier casductinggaseous refrigerant from said zone to one of said chambers in saidmuilier; a restricted said zone for conducting gaseous refrigerant ,from

f aperture in said muiiler casing and arranged to eous refrigerar'rtfrom said mumer to saidlcm f provide for the escape from said mufflercasing conduit for conducting gaseous refrigerant from another o'fsaidchambers in said muiiler casing Qing, a relatively long restricted tubehaving an Y @inlet opening arranged in said zone` for conf any lubricantaccumulating therein, and a l0 "ing, an intake muiiier for saidcompressor arranged in said enclosing lcasing, said muiiier having acasing, means constituting a transverse frigerant in the upperportionnthereof',.means operated by said motor for establishing -a zonea'restricted passage therein forming a plurality

